Fluid operated clutch



March '22, 1949. 5, ass AL 2,464,975

FLUID OPERATED CLUTCH Filed Aug. 19, 1944 INVENTOI (5. Thomas .B. GLZDZDS Robe rt BY Bram/2f Patented Mar. 22, 1949 2,464,975 rum) OPERATED CLUTCH Thomas B. Gibbs and Robert E. Brandt, Delavan,

Wis., assignors to The George W. Borg Corporation, Chicago, Ill., a corporation of Delaware Application August 19, 1944, Serial No. 550,270

' 8 Claims. (01. 192-85) 1 The present invention relates in general to fluid operated clutches, and more in particular to clutches of this character which are adapted for use in coupling a rotating element such as a shaft to its driving element. As specifically disclosed herein, the invention is an air controlled clutch for coupling the spindle of a combined automatic lathe and hobbing machine to the hob motor.

This application is for subject matter disclosed in application Serial Number 468,060. filed December 7, 1942, now Patent Number 2,415,206, issued February 4, 1947, in which the combined automatic lathe and hobbing machine referred to is. disclosed and claimed.

The invention will be described more in detail hereinafter with reference to the accompanying drawing, in which Fig. 1 is a view showing the clutch and the associated parts of the machine to which it is applied, the clutch being shown partly in section; and

Fig. 2 is a partial section taken on a different plane and showing the passage for admitting compressed air to the clutch.

The machine to which the invention is applied is adapted for the-manufacture of small pinions from rod stock and includes a hollow spindle and collet for holding and rotating the rod stock, a set of radially disposed tools for turning the pinion shaft, and a hob located just beyond the tools in the direction ofthe head stock motion for cutting the pinion teeth. In the operation of the machine, the end of the stock'is first turned down in known manner to form the shaft at one end of the pinion which is being made. When this operation is completed, the head stock is moved quickly forward to bring the stock into the vicinity of the hob, and the hobbing operation is performed while the incompleted pinion is still part of the stock. As soon as the hobbing operation is finished, the head stock is returned the proper distance to bring that portion of the stock from which the other end of the pinion shaft is to be formed 'into operative relation to the tools, and the shaft is finished by further turning operations. The completed pinion is then cut off from the stock. whereupon the collet is opened and the head stock is moved back to get a fresh grip on the stock preparatory to making another pinion.

A motor is provided for driving the spindle and a. separate motor is provided for driving the hob. During turning operations the spindle is driven by the spindle motor, to which it is always connected. During bobbing operations the power is 2 shut off from the spindle motor, which is allowed to run free, and the spindle is driven by the hobbing motor through the medium of suitable gears and the clutch which forms the subject matter of the present invention. The clutch is used to uncouple the spindle from the hob motor dur ng turning operations, when the spindle is driven by the spindle motor, and to couple the spindle to the hob motor during hobbing operations, when it is necessary to drive the spindle at a speed which bears a definite relation to the hob speed.

Referring now to the drawing, the head stock is partially shown in Fig. 1, where it is indicated by the reference character 20. The hollow spindle is indicated at 54 and is supported on the head stock by means of ball bearings in known manner. The spindle .is provided with a pulley 55 and is driven fromthe spindle motor by means including the belt 56.

The drive from the hob motor includes a gear which is in mesh with the wide faced pinion H,

the latter being long enough so that the gear and pinion stay in mesh in any head stock position. The'pinion 1| drives a gear in the clutch, as will be explained shortly. The clutch is concentric with the spindle and is contained within the clutch housing 53.

One of the several sets of ball bearings which support the spindle is located just to the left of.

the clutch housing and is shown in Fig. 1. The head stock 20 has a rounded upwardly projecting extension 20' which at its right hand end is a continuation of the boss 51 at the end of the head stock.. This boss has a machined circular end surface concentric with which the end of the head stock including extension 20 is bored out to receive the outer ball races 58. The inner ball races 59 are clamped against the shoulder 60 on the spindle 54 by means of the tubular sleeve 6|,the clutch member 62 and the nut 63. The clutch member 62 is prevented from turning on the spindle by means of a key 64.

The reference character indicates the clutch bearing member, which is generally of cylindrical shape and has a flange 66 which engages the machined end surface of the boss 51. The clutch bearing member and the clutch housing 53 are secured to the head stock against the boss 51 by means of screws such as 61. The screw 61 passes through the head stock extension 20' and is threaded into the cover member 68. The other screws are threaded into the head stock.

The clutch housing 53 is generally cup-shaped and has an annular interior ridge 69 at the bottom through which the holes are drilled for the screws such as 61. The other end of the clutch housing is closed by the circular plate 18. The

As mentioned hereinbefore, one of the clutch.

members is indicated at 82 and is rigidly secured to the spindle. The other clutch member is indicated at 15 and is formed integrally with the gear 18 which is in mesh with the long pinion I When the clutch is disengaged, the position in which it is shown in the drawing, the clutch member 15 is rotatable on the clutch bearing member 65.

The clutch member 15 is urged to the right by three coil springs such as 11 which are located in recesses in the clutch member. These springs are compressed between the clutch member'and the bronze bearing ring 18, which rotatably engages the air seal ring 18. It will be noted that there is an annular air chamber 80 inside the gear 18 between the air seal ring 18 and the end of clutch member 15.

The clutch member I5 is urged to the left by air pressure in the annular air chamber 8|, which is closed by an air seal ring 82, clamped against the shoulder 83 on the clutch bearing member 85 by means of the nut 84. Compressed air is supplied to the chamber 8| by means of an input pipe (not shown) having a coupling which is threaded into an opening 88 at the bottom of the clutch housing. The opening 88 is shown in Fig. 2, which is a section taken on a plane which is angularly displaced from the sectional plane of Fig. 1. From the bottom of opening 86 a hole 81 is drilled through the bottom of the clutch housing and the clutch bearing member 85 to intersect the longitudinal hole 88 drilled in the clutch bearing member. The hole or channel 88 is closed at one end by a plug 88 and at the other end communicates with the air chamber 8| by way of a hole 98 drilled in the clutch bearing member.

The clutch bearing member 65 also has a longitudinal hole or channel 8|, Fig. 1, which is similar to the channel 88, Fig. 2. The channel 9| is connected with the air chamber 8| by a hole 82, and is connected withthe air chamber 88 by a hole 98.

The valve through which compressed air is sup- I plied to the input pipe above referred to is so arranged that in its open position the pipe is connected to the compressed air supply source while in its closed position the pipe is opened to the at-.

mosphere. When the air chamber 8| is at atmospheric pressure the springs I1 move the clutch member 15 to the right and hold it in engagement sate for the difference between the force exerted by the springs TI and the force exerted by the compressed air in air chamber 8|.

The valve above referred to may be operated automatically in proper timed relation to the operation of other parts of the complete machine, as will be readily understood. During the initial turning operations the valve is open and supplies compressed air to the annular chamber 8|, whereby the clutch is maintained in disengaged position. At this time the spindle is driven by the spindle motor by means of belt 58. When the hobbing operation is about to start the valve is closed, shutting off the compressed air and venting the input pipe. This reduces the pressure in chamber 8| to atmospheric pressure and allows the clutch to engage, with the result that the spindle is driven from the hob motor, the drive including the pinion 1| and gear 16. Upon the completion of the hobbing operation, the valve is again opened to admit air to the chamber 8| to disengage the clutch, the spindle motor is started, and the final turning operations required are performed.

It will be understood that although the invention has been described as applied to a certain specific machine, it is well adapted for use in connection with other machines, and in many cases may be used without modification. Changes in construction may be made, however, to adapt the clutch to use in special situations, or for other reasons, and we do not, therefore, wish} to be restricted to the exact form and construction disclosed herein, but desire to include and have protected by Letters Patent all forms and modifications of the invention which come within the scope of the appended claims.

We claim:

1. In a machine tool for making parts from rod stock, a tubular spindle for rotating the stock, two clutch members coaxially disposed with reference to said spindle, a first one of said members being fixed to the spindle, a bearing for supporting the second clutch member independent of the spindle, means for rotating said second mentioned clutch member on said bearing, resilient means for sliding the second clutch member on said bearing to engage said clutch members, and an annular air said clutch members.

with the clutch member 82. In this condition the clutch is engaged and rotation of the pinion or gear 18 rotates the spindle 58. It should be observed also that the movement of the clutch member 15 to the right closes the air hole 82. When compressed air is'supplied to the air chamber 8| the clutch member 15 is moved to the left to disengage the clutch. When the clutch member 15 arrives at about the position in which it is shown in Fig. 1, the hole 92 is partly opened and compressed air leaks out of air chamber 8| into air chamber 80. The movement ofthe clutch member I8 to the left stops when the air pressure in air chamber 80 becomes high enough to compenchamber including a part of said clutch member to which compressed air is admitted to disengage 2. In a machine tool for making parts from rod stock, a tubular spindle for rotating the stock, two clutch members coaxially disposed with reference to said spindle, a first one of said members being fixed to the spindle, a bearing for supporting the second clutch member independent of the.

spindle, means for rotating said second mentioned clutch member on said bearing, resilient means for sliding the secondclutch member on said bearing to engage said clutch members, an annular air chamber including a part of said second clutch member to which compressed air is admitted to disengage said clutch members, a second air chamber including an oppositely disposed part of said second clutch member, and an air passage connecting said air chambers which is closed when the second clutch member is in engaged position and is opened by movement of said second clutch member to disengaged position. I

3. In a clutch for driving a rotatable shaft 'or spindle, two clutch members coaxially disthe second clutch member for both rotary and axial motion, said means comprising a fixed cylindrical bearing member, said axial motion said last means including an air passage formed in said bearing member.

4. The combination, with a rotatable shaft or spindle, of a clutch comprising two clutch mem- -bers coaxially disposed with reference to said ber in one direction comprising an annular air chamber concentric with said spindle, a second air chamber concentric with said spindle, and means responsive to movement of said second clutch member when air is admitted to said first air chamber for admitting air to said second air chamber to arrest such movement.

5. The combination, with a rotatable shaft or spindle, of a clutch comprising a first clutch member fixed to said shaft, a second clutch member supported for rotation relative to said shaft and movable axially of the shaft relative to said first clutch member, two air chambers in said clutch having a common wall formed by a part of said second clutchmember, and two air passages in the clutch for supplying compressed air to said air chambers, respectively, to controlthe axial movement of said second clutch member, one of said air passages being connected to its associated air chamber by a port which is opened and closed by movement of said second clutch member.

6. The combination, with a rotatable shaft or spindle, of a clutch comprising a clutch member fixed to said shaft, a fixed cylindrical bearing member surrounding said shaft, a second clutch member rotatably supported on said bearing member and axially movable thereon relative to first clutch member, two annular air chambers surrounding said bearing member for controlling the axial movement of said second clutch member, an air passage formed in said bearing mem formed in said bearing member for supplying compressed air from said first air chamber to said second air chamber.

7. The combination, with a rotatable shaft, of a clutch comprising two clutch members concentric with the shaft, one of said clutch members having a driving connection with the shaft and the other being rotatable relative to the shaft, means for producing a controlled movement of one clutch member axially of the shaft relative to the other clutch member, said means including two annular air chambers surrounding said shaft on opposite sides of the axially movable clutch member, means for supplying compressed air to one of said air chambers, and means responsive to movement of said axially movable clutch member for supplying compressed air to the other of said air chambers.

8. The combination, with a rotatable shaft or spindle, of a clutch comprising two clutch members concentric with the shaft, one of said clutch members having a driving connection with the shaft and the other clutch member being rotatable relative to the shaft, one of said clutch members also being axially movable along the shaft relative to the other clutch member, means including two annular air chambers surrounding said shaft on opposite sides of the axially movable clutch member for controlling the axial movement thereof, each air chamber having a movable wall formed at least in part by a part of said axially movable clutch member, and air passages in said clutch for supplying compressed air to said air chambers.

THOMAS B. GIBBS. ROBERT E. BRANDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

